“Self-inflicted gunshots kill more Americans every day,” said Griffin Edwards, Ph.D., lead author of the paper and professor in the UAB Collat School of Business. “We wanted to look at ways to reduce these common and oftentimes more costly sources of firearm-related deaths. Our study looks at delaying the purchase of a handgun in correlation with the reduction of firearm-related suicide rates.”

The study, published in The Economic Journal, found that gun purchase waiting periods do not prevent homicides; but they can save hundreds of lives each year — maybe even thousands — that suicide would have ended.

Sophisticated statistical analysis is used to connect changes in states’ waiting period laws to changes in homicide and suicide rates over the period from 1990-2013. Investigators found substantial reductions in gun-related suicide deaths, with no corresponding increase in other forms of suicide.

“There were 32 states without a mandatory purchase delay when we conducted the study,” Edwards said. “If these states were to adopt one handgun purchase delay policy, an estimated 600 lives per year could be saved.”

The study estimates the effect reliably only for handgun waiting periods. If these laws were to apply to rifles and shotguns as well, the number of lives saved would likely be larger, according to the study.

No evidence was found that individuals unable to purchase a firearm quickly substitute a different method of suicide successfully.

“Even if people switch suicide methods, firearms are by far the deadliest,” Robinson said. “Surviving one suicide attempt is almost always enough to prevent suicide, since only 10 percent of those who survive a suicide attempt go on to die by suicide.”

While the study did not directly measure the effect of waiting periods on mass shootings, the study finds no consistent evidence that waiting periods reduce homicides, and mass shootings tend to be planned over a longer period of time than typical homicides.

While mass shootings are appalling and garner massive media attention, the daily realities of gun violence — suicides in particular — are much deadlier, according to the research. On average, about as many people take their own lives with a firearm every single day in the United States as the number of people who died in the largest mass shooting in American history. Furthermore, while homicide rates have been declining across the country since the early 1990s, suicide rates have been on the rise since the mid-2000s.

“Gun policy is often difficult because policymakers must attempt to weigh the value that many of their constituents place on their right to access firearms against the social cost of gun violence,” Edwards said. “But waiting periods are somewhat unique in that such policies do not ask law-abiding citizens to forfeit access to firearms, but rather ask them to delay a purchase for a short period of time. Given that these policies can potentially save hundreds if not thousands of lives a year, the benefits seem worth the cost.”